Uptake, translocation, weathering and speciation of gold nanoparticles in potato, radish, carrot and lettuce crops.

Extensive use of nanomaterials in agriculture will inevitably lead to their release to the environment in significant loads. Thus, understanding the fate of nanoparticles in the soil-plant environment, and potential presence and consequent implication of nanoparticles in food and feed products, is required. We study plant uptake of gold nanoparticles from soil, and their distribution, translocation and speciation (in terms of particle size change and release of ionic Au) in the different plant tissues of four important crops (potato, radish, carrot and lettuce). Our new analytical protocol and experiments show the feasibility of determining the presence, concentration and distribution of nanoparticles in different plant parts, which differ from plant to plant. Critically, we identify the evident capacity of plants to break down (or substantially change the properties of) nanoparticles in the rhizosphere prior to uptake, as well as the evident capacity of plants to reorganize ionic metals as nanoparticles in their tissues. This could lead to nanoparticle exposure through consumption of crops.

Evaluación de historias clínicas elaboradas en salas de hospitalización de medicina interna del Hospital Escuela / Evaluation of medical history completed in Internal Medicine Wards in the Hospital Escuela

La historia clínica es bastión en la práctica médica, debe ser elaborada de forma sistemática y evaluarse objetivamente. En el Hospital Escuela no existe un modelo único ni forma de evaluarla, debido a ello se realizó el presente estudio. Objetivo: Evaluar la estructura de la Historia Clínica (HC) elaborada por estudiantes de la Facultad de Ciencias Médicas. Métodos: Se realizó un estudio transversal descriptivo, mediante la revisión de 626 expedientes de pacientes de salas de Medicina Interna en el periodo del 13 de noviembre 2010 al 23 de febrero 2011, con la finalidad de analizar la estructura de las HC; estas se cotejaron con una HC modelo que fue el instrumento de trabajo, la estructura del modelo se basó en libros de textos y en el programa de la asignatura Introducción a la Clínica. El estudio se realizó en 3 etapas: validación del instrumento en 12 expedientes, revalidación o ensayo preliminar en 100 historias de 302 expedientes y fase final: evaluación de 100 historias de 312 expedientes. Resultado: de las 100 historias evaluadas, 55 eran de pacientes mujeres, 31 de hombres y en 14 esta información no se consignó. Los datos generales fueron consignados en las 100 HC; al describir el síntoma principal se utilizó lenguaje técnico, presente en 91 HC, en 99 se encontraba descrita la historia de la enfermedad actual aunque redactada en forma confusa, en 95 no se realizó en forma lógica y solamente en 9 HC se plasmó la evolución en forma coherente y lógica. El uso de parámetros semiológicos se describió en 99 HC dificultando el análisis de las mismas, uno de los parámetros de importancia es el tratamiento recibido por el paciente, se describió en 29 historias y en 42 se consignó los atenuantes y precipitantes. Las funciones orgánicas generales fueron muy bien descritas en 99 HC, agregándose en este apartado la descripción por órganos, aparatos y sistemas. Los antecedentes no patológicos y patológicos se describieron en 85 y 98 respectivamente...

Growth inhibitory effect of grape phenolics against wine spoilage yeasts and acetic acid bacteria.

This paper investigates the in vitro antimicrobial potential of 15 grape phenolic compounds of various chemical classes (phenolic acids, stilbenes and flavonoids) using the broth microdilution method against yeasts and acetic acid bacteria frequently occurring in deteriorated wine. Pterostilbene (MICs=32-128 µg/mL), resveratrol (MICs=256-512 µg/mL) and luteolin (MICs=256-512 µg/mL) are among six active compounds that possessed the strongest inhibitory effects against all microorganisms tested. In the case of phenolic acids, myricetin, p-coumaric and ferulic acids exhibited selective antimicrobial activity (MICs=256-512 µg/mL), depending upon yeasts and bacteria tested. In comparison with potassium metabisulphite, all microorganisms tested were more susceptible to the phenolics. The results revealed the antibacterial and antiyeast effects against wine spoilage microorganisms of several highly potent phenolics naturally occurring in grapes. These findings also provide arguments for further investigation of stilbenes as prospective compounds reducing the need for the use of sulphites in winemaking.

Satisfacción del paciente oncológico con la atención médica recibida en el Hospital General San Felipe y Hospital Escuela / Cancer patients satisfaction with the medical care received at the Hospital General San Felipe y Hospital Escuela

La satisfacción del paciente al recibir atención médica depende del cumplimiento de sus necesidades, expectativas y deseos con respecto al establecimiento de la relación médico-paciente, calidad y cantidad de información recibida y apoyo psicológico. Para conocer aspectos en el paciente oncológico, se realizó un estudio tipo transversal en 276 pacientes con cáncer atendidos en consulta externa y salas de hospitalización de Oncología en el Hospital General San Felipe (HGSF) y Hospital Escuela (HE). Objetivo: Medir el nivel de satisfacción de pacientes con cáncer al ser atendidos por médicos en los departamentos de Oncología. Material y Métodos: Previo consentimiento informado se aplicó a los pacientes un cuestionario por escrito de ocho preguntas relacionadas a la calidad de atención brindada a ellos por los oncólogos que laboran en los departamentos respectivos en el HGSF y HE. Resultados: El 44.9% de los pacientes tenía antecedentes de cáncer en su familia, 90.9% admitió tener una relación con su médico de buena a excelente, la calidad de información brindada fue satisfactoria en 82.7%, sin embargo, a los pacientes les gustaría que su médico fuera más amistoso, al 41.7% se le brinda apoyo psicológico y el 85.9% desean saber su pronóstico y que su familia esté enterada de éste; en caso de exámenes o tratamientos no disponibles desean se les informe al respecto y tratarían de obtenerlos. Conclusión: En este estudio los pacientes no están satisfechos con el nivel de atención médica brindada ya que desean cambiar algún aspecto en la relación con el médico, desean que dicha relación sea mejorada y la mayoría piensa que no se les brinda apoyo psicológico, con respecto a su pronóstico de vida la mayoría quieren enterarse del mismo y que sus familiares se enteren, por tanto el médico debería de explicar con detalle este aspecto...

Hydroxylated anthraquinones produced by Geosmithia species.

Geosmithia fungi are little known symbionts of bark beetles. Secondary metabolites of lilac colored species G. lavendula and other nine Geosmithia species were investigated in order to elucidate their possible role in the interactions of the fungi with environment. Hydroxylated anthraquinones (yellow, orange, and red pigments), were found to be the most abundant compounds produced into the medium during the submerged cultivation. Three main compounds were identified as 1,3,6,8-tetrahydroxyanthraquinone (1), rhodolamprometrin (1-acetyl-2,4,5,7-tetrahydroxyanthraquinone; 2), and 1-acetyl-2,4,5,7,8-pentahydroxyanthraquinone (3). Compounds 2 and 3 (representing the majority of produced metabolites) inhibited the growth of G+-bacteria Staphylococcus aureus and Bacillus subtilis with minimum inhibitory concentration of 64-512 microg/mL. Anti-inflammatory activity detected as inhibition of cyclooxygenase-2 was found only for compound 3 at 1 and 10 microg/mL. Compound 2 interfered with the morphology, compound 3 with cell-cycle dynamics of adherent mammalian cell lines.

Theory of stochastic resonance for small signals in weakly damped bistable oscillators.

The response of a weakly damped bistable oscillator to an external periodic force is considered theoretically. In the approximation of weak signals we can write a linearized equation for the signal and the corresponding nonlinear equation for the noise. These equations contain two unknown parameters: An effective stiffness and an additional damping factor. In the case of the weakly damped bistable oscillator, considered here, the two-dimensional Fokker-Planck equation corresponding to the equation for the noise can be solved approximately by changing to a slow variable ("energy") and applying a method of successive approximation. This approach allows us to find the unknown parameters and to calculate the amplitude ratio of the output and input signals, i.e., the gain factor.

Experimental evidence, numerics, and theory of vibrational resonance in bistable systems.

We consider an overdamped bistable oscillator subject to the action of a biharmonic force with very different frequencies, and study the response of the system when the parameters of the high-frequency force are varied. A resonantlike behavior is obtained when the amplitude or the frequency of this force is modified in an experiment performed by means of an analog circuit. This behavior, confirmed by numerical simulations, is explained on the basis of a theoretical approach.

Self-oscillations in ring Toda chains with negative friction.

We study here the different modes of self-oscillations in ring Toda chains with Rayleigh-type negative friction. Assuming that at small friction the shape of self-oscillations is close to one of the known Toda solitonlike solutions we use analytical methods in combination with numerical ones for study of the self-oscillations. We calculate explicitly for a Toda chain consisting of N elements the N+1 different modes of self-oscillations. Among them two modes correspond to left and right rotations of the chain as a whole with a constant velocity Each of the other N-1 modes represents a combination of solitonlike oscillations and a rotation with a velocity depending on the mode number. Only for the mode corresponding to antiphase oscillations of the chain neighboring elements (such oscillations are possible for an even N) the constant component of the velocity is equal to zero.

Exhibition of intrinsic properties of certain systems in response to external disturbances.

Two systems, which are models of biological processes, are considered. These systems are notable for responding to different external actions nearly alike. This is associated with the fact that an external action excites only their natural intrinsic motions. Two kinds of external actions, harmonic and random, are studied. It is shown that each of them induces a transition to a new state that can be treated as a peculiar kind of phase transitions. Characteristics of these phase transitions are found.

[A model of the respiratory control system]. / Ob odnoi modeli sistemy upravleniia dykhaniem.

A modification of the Mackey-Glass model for a respiration control system is proposed. The equations corresponding to the proposed model were built. A solution of the equations was obtained, which corresponds to the Cheyne-Stokes irregular respiration.